While various apparatuses such as a keyboard, a mouse, and a touch panel have been used as an interface for input to a computer, other various input interfaces have also been proposed so as to respond to voices of various users.
Under these circumstances, multi-modal interfaces have been noted in recent years. “Multi-modal” refers to multiple modes and a multi-modal interface refers to an interface using multiple media. Typically, a multi-modal interface refers to an interface combining voice information and video information. Also, nonverbal interfaces using nonverbal information rather than using voice information are known (Non-Patent Document 1).
[Non-Patent Document 1] Takao Kurokawa “Non-verbal Interface Human Communication Engineering Series,” Ohmsha, 1994.